Migaloo, the famous white whale, has been spotted off the New South Wales mid-north coast and could soon be in Queensland waters, where hefty new fines apply to anyone who gets too close.
Queensland has declared Migaloo a special-interest whale, which means no one can bring a boat or jet ski closer than 500 metres or fly an aircraft within 2,000 feet of the humpback.
Environment Minister Kate Jones says anyone found in breach of these conditions faces a fine of up to $16,500.
For other whales, the limits are 100 metres for a boat and 300 metres for jet skis and the like. In these cases, a maximum penalty of $12,000 applies.
"Migaloo has been declared a special-interest whale, granting him more space to swim up the Queensland coast," Ms Jones said.
"The whale-watching regulations are there to protect the whales, but also to protect people from these huge, unpredictable mammals.
"Adult humpbacks can weigh more than a fully-loaded semi-trailer so you need to stay out of their way."
She says a white whale believed to be Migaloo was sighted off Tacking Point at Port Macquarie and is expected to be in Queensland waters this week.
The first reported sighting of Migaloo was in 1991 off Byron Bay, when he was three to five years old.
His unusual colouring makes him easy to track.
In winter humpbacks migrate north to warm tropical waters, where females give birth.
They return south to their Antarctic feeding grounds in spring.